10. Certain Baby Dolphins and Whales Never Sleep

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Ever seen a motionless baby whale? We didn’t think so. For the first month of their lives, newborn bottlenose dolphins and killer whales never sleep but remain mobile 24 hours a day. Similarly, sharks have no air bladders, so they have to swim constantly or they'll sink. On the luckier end of the scale are albatrosses, who can sleep while in flight. Giraffes tend to get a lot done, as they rarely sleep more than 20 minutes a day.